This invention relates to a print engine. The invention has particular application in a print engine for use in an instantaneous print, digital camera. More particularly, the invention relates to a pump assembly for a print engine.
The page width printhead of the present invention uses a nozzle guard through which ink droplets are ejected. It is important to maintain the nozzle guard free of foreign particles and detritus so that the ink is not contaminated by such foreign matter and microelectromechanical systems (MEMS) ink ejection devices are not blocked by the foreign matter. One of the simplest ways of achieving this is to blow out over a surface of the nozzle guard and a zone between the nozzle guard and that surface of a silicon wafer of the printhead carrying the MEMS devices.
By xe2x80x9cpage widthxe2x80x9d is meant that the printhead prints one line at a time on the print media without traversing the print media, or rastering, as the print media moves past the printhead.
In addition, it is desirable to make the print engine as compact as possible in order to reduce the size of the camera in which the print engine is employed.
According to the invention, there is provided a pump assembly for a print engine, the print engine having a printhead employing a fluid cleaning arrangement, the pump assembly including
a housing defining a fluid inlet and a fluid inlet;
an impeller for drawing fluid through the inlet and ejecting it through the outlet; and
a drive means for rotatably driving the impeller, the drive means being a drive means of the print engine, which controls feeding of print media to the printhead for printing of an image on the print media.
The inlet may communicate with a filter means, which filters the fluid, via a coupling device in the form of an air inlet pin. It is envisaged that the filter means will be incorporated in a print cartridge to be replaced when the print cartridge is replaced such that air blown over the printhead by the pump assembly is filtered prior to being ejected from the pump assembly.
The pump may include a housing in which the impeller is rotatably mounted, a part of the housing being defined by a chassis which supports the coupling device and which defines a fluid supply path which supplies the fluid to the printhead.
The drive means may be a drive motor connected to the impeller by a first gear arrangement and to a feed means of a print roll of a print cartridge of the print engine via a second gear arrangement. Preferably, the drive motor is a stepper motor so that air is supplied to the printhead only when the printhead is operational.